FUNCTIONAL CLAIMS REQUIRE MORE THAN JUST TRIAL-AND-ERROR INSTRUCTIONS FOR SATISFYING THE ENABLEMENT REQUIREMENT
| January 5, 2024
Baxalta Inc. v. Genentech, Inc.
Decided: September 20, 2023
Moore, Clevenger and Chen. Opinion by Moore
Summary:
Baxalta sued Genentech alleging that Genentech’s Hemlibra product infringes US Patent No. 7,033,590 (the ‘590 patent). Genentech moved for summary judgment of invalidity of the claims for lack of enablement. The district court granted summary judgment of invalidity. Upon appeal to the CAFC, the CAFC affirmed invalidity for lack of enablement citing the recent Supreme Court case Amgen v. Sanofi.
Details:
Baxalta’s patent is to a treatment for Hemophilia A. Blood clots are formed by a series of enzymatic activations known as the coagulation cascade. In a step of the cascade, enzyme activated Factor VIII (Factor VIIIa) complexes with enzyme activated Factor IX (Factor IXa) to activate Factor X. Hemophilia A causes the activity of Factor VIII to be functionally absent which impedes the coagulation cascade and the body’s ability to form blood clots. Traditional treatment includes administering Factor VIII intravenously. But this treatment does not work for about 20-30% of patients.
The ‘590 patent provides an alternative treatment. The treatment includes antibodies that bind to Factor IX/IXa to increase the procoagulant activity of Factor IXa which allows Factor IXa to activate Factor X in the absence of Factor VIII/VIIIa. Claim 1 of the ‘590 patent is provided:
1. An isolated antibody or antibody fragment thereof that binds Factor IX or Factor IXa and increases the procoagulant activity of Factor IXa.
The ‘590 patent describes that the inventors performed four hybridoma fusion experiments using a prior art method. And using routine techniques, the inventors screened the candidate antibodies from the four fusion experiments to determine whether the antibodies bind to Factor IX/IXa and increase procoagulant activity as claimed. Only 1.6% of the thousands of screened antibodies increased the procoagulant activity of Factor IXa. The ‘590 patent discloses the amino acid sequences of eleven antibodies that bind to Factor IX/IXa and increase the procoagulant activity of Factor IXa.
Citing Amgen Inc. v. Sanofi, 598 U.S. 594 (2023), the CAFC stated that “the specification must enable the full scope of the invention as defined by its claims, allowing for a reasonable amount of experimentation. Citing additional cases, the CAFC stated “in other words, the specification of a patent must teach those skilled in the art how to make and use the full scope of the claimed invention without undue experimentation.”
Baxalta argued that one of ordinary skill in the art can obtain the full scope of the claimed antibodies without undue experimentation because the patent describes the routine hybridoma-and-screening process. However, the CAFC stated that the facts of this case are indistinguishable from the Amgen case in which the patent at issue provided two methods for determining antibodies within the scope of the claims. In Amgen, the Supreme Court stated that the two disclosed methods were “little more than two research assignments,” and thus, the claims fail the enablement requirement.
The CAFC described the claims in this case as covering all antibodies that (1) bind to Factor IX/IXa; and (2) increase the procoagulant activity of Factor IXa, and that “there are millions of potential candidate antibodies.” The specification only discloses amino acid sequences for eleven antibodies within the scope of the claims. Regarding the method for obtaining the claimed antibodies, the specification describes the following steps:
(1) immunize mice with human Factor IX/IXa;
(2) form hybridomas from the antibody-secreting spleen cells of those mice;
(3) test those antibodies to determine whether they bind to Factor IX/IXa; and
(4) test those antibodies that bind to Factor IX/IXa to determine whether any increase procoagulant activity.
The CAFC stated that similar to Amgen, this process “simply directs skilled artisans to engage in the same iterative, trial-and-error process the inventors followed to discover the eleven antibodies they elected to disclose.”
The Supreme Court in Amgen also stated that the methods for determining antibodies within the scope of the claims might be sufficient to enable the claims if the specification discloses “a quality common to every functional embodiment.” However, no such common quality was found in the ‘590 patent that would allow a skilled artisan to predict which antibodies will perform the claimed functions. Thus, the CAFC concluded that the disclosed instructions for obtaining claimed antibodies, without more, “is not enough to enable the broad functional genus claims at issue here.”
Baxalta further argued that its process disclosed in the ‘590 patent does not require trial-and-error because the process predictably and reliably generates new claimed antibodies every time it is performed. The CAFC stated that even if a skilled artisan will generate at least one claimed antibody each time they follow the disclosed process, “this does not take the process out of the realm of the trial-and-error approaches rejected in Amgen.” “Under Amgen, such random trial-and-error discovery, without more, constitutes unreasonable experimentation that falls outside the bounds required by § 112(a).”
Baxalta also argued that the district court’s enablement determination is inconsistent with In re Wands. The CAFC disagreed stating that the facts of this case are more analogous to the facts in Amgen, and the Amgen case did not disturb prior enablement case law including In re Wands and its factors.
Comments
When claiming a product functionally, make sure your specification includes something more than just trial-and-error instructions. The CAFC suggested in this case that the enablement requirement may be satisfied if the patent discloses a common structural or other feature delineating products that satisfy the claims from products that will not. The CAFC also suggested that a description about why the actual disclosed products perform the claimed functions or why other products do not perform the claimed function would be helpful for satisfying the enablement requirement.
